Royal Purple gets smacked down big time

[Greg Good Cylinder Heads]

I will respectfully disagree that a high performance gasoline engine can't take advantage of detergents.

I did not say a Viper should *not* have detergent in its oil. I opined that the level of it in the diesel oils is excessive for a Viper. Any street driven vehicle *needs* a detergent package in the oil. No argument there. Only a break-in oil can be free, or almost free, of it. The reason I am against putting more detergent than necessary into an engine is that detergents are polar molecules, as are zinc molecules. Excess detergent reduces the effectiveness of zinc.

Your comment about how zinc does little good with all that detergent implies you believe there a competition for metal sites between the detergents and the anti-wear additive (and friction modifiers). In a properly formulated oil this is not a problem. In fact, as an engine builder, I am sure you are aware of the now-common problem during break-in with a flat tappet engine and today's oils - cam failures are common. The "cure" has been to use the cam manufacturer's break in oil additive or a diesel oil! Once builders realized it was the reduced ZDDP causing the problem, companies like Joe Gibbs Racing oil have been selling a specific break-in oil.

I'm not implying it, I'm saying it straight out. The *proper formulation* of an oil depends on the engines level of modification. A stock engine with low valve lift, low springs pressures, making stock power levels can *get by* with a higher ratio of detergent such as the Rotella has. A 600 rwhp car with .600" lift, 160 seat/440 open spring pressure, etc .etc. needs more protection. We're asking the same surface areas in the engine to carry higher loads and all of a sudden the additive package requirements need to shift towards protecting the engine itself rather than the cats. Zinc and detergent molecules are *both* polar and there is only so much real estate in an engine for them to attach to.....so there *is* competition between detergent and zinc for access to steel surfaces. That's why break-in oil has very little detergent in it...for as much zinc as possible to be *activated* and protect the engine.

Another major difference between gasoline and diesel use is the amount of soot that gets into diesel oil. The formulation therefore includes higher dispersant amounts, which keep the soot suspended prevent the oil from thickening, and forming sludge in low flow areas. I am sure most piston-heads on this board have seen sludge in their gasoline engine, so it argues that more dispersant (via a diesel oil) is useful. Even Dodge is moving to more diesel like oils - the Mobil 1 0W-40 now used in Vipers is formulated for use in the european passenger car diesels.

A Dodge Viper that is seeing regular oil changes does not need as much detergent as a diesel engine serviced at longer intervals. The extra detergent is not put to use, and even hinders the zinc from attaching to engine surfaces and forming a protective layer.




Overall a diesel oil may be overkill. If so, then a synthetic base oil is also overkill. However, when the engine starts to stretch the service requirements far into one direction, whether it be high operating temperatures, high levels of oil contamination, or high wear conditions... or all of them simulataneously, a diesel (universal) oil will provide all the vitamins the engine needs, with complete confidence and with no downside.

API is concerned with catalytic converters lasting a long time, hence reduced zinc. The same zinc that attaches (if the detergent package will let it) to and protects engine surfaces also coats the catalyst, rendering it ineffective over time. I honestly don't want an API oil anymore, because if it's API certified...it has the wrong additive package to protect a high horsepower engine.

That's just my .02. That and 73 more cents will buy you a soft drink.

 

[Kevan]

If I subscribe to this thread, does that make me a geek?


Excellent info!

 

[Tom F&L GoR]

API is concerned with catalytic converters lasting a long time, hence reduced zinc. The same zinc that attaches (if the detergent package will let it) to and protects engine surfaces also coats the catalyst, rendering it ineffective over time. I honestly don't want an API oil anymore, because if it's API certified...it has the wrong additive package to protect a high horsepower engine.

That's just my .02. That and 73 more cents will buy you a soft drink.

It's not the zinc, it's the phosphorus component of the antiwear additive. Strictly speaking, only the ILSAC rated oils (starburst "for gasoline engines" logo on the front) must meet the lowered phosphorus level, and those are xxW30 and lower viscosity grades; not yyW40 and higher. An oil can be API certified and not need to be ILSAC.

I have never seen any technical indication that detergents shorten the life of catalytic converters as phosphorus supposedly does. You may be mixing up that concept with the plugging of particulate filters that are only on diesel engines, not on gasoline engines. This is why even diesel oils are moving to lower ash, sulfur, and phosphorus.

You are repeating the ZDDP-detergent competition for metal surfaces. You must acknowledge that engine builders successfully use diesel oil as a break-in oil, so the antiwear function is obviously doing it's job and is significantly different (better) than an ILSAC gasoline engine oil.

Greg, if you want a second opinion, give me a call. You must have an engine oil you're happy with (what is it?) but to say an API certified oil has the wrong additive package can be factually disputed many ways. I'd love to find out how you came to your conclusions and also share what I've learned with you.

Part of my curiousity comes from knowing that every race team Texaco sponsored used off-the-shelf engine oil to begin with, then we modified as we learned what else they wanted. So to maintain the advertising that Jaguar F1, Robert Yates, and Newman Haas used "Havoline" we only added to the formulation and never took anything out. Each one of your comments concludes with a specific zinc vs. detergent warning and that experience differs with mine. It would seem if true, diesel trucks would have to be wearing themselves out left and right, yet they go 600,000 to 1,000,000 miles between overhauls.

 

[Greg Good Cylinder Heads]

Correct, it is actually the phosphorous in the zinc dialkyl dithiophosphate that harms the converters. We toss aound the terms zinc, ZDP, and ZDDP to describe that particular molecule, but it is the phosphorous that causes the problem with cats.

You can talk to ten performance enthusiasts and get ten different opinions on oil. Guys I know like Red Line (a Pro Stock engine builder I know said it makes a little more power than RP). Others like Amsoil, Royal Purple, Brad Penn (the old Kendall), etc. etc. the list goes on.

I prefer the Gibb's oil over everything else right now. The way that the detergent and zinc additive packages interact was described in detail to me by Lake Speed Jr. I trust him, and his oils have done well for me. The Viper oiling system is junk by racing standards, and the fact that some of the engines I've built have stayed together under the abuse they've seen is a testamnet to the Gibbs oil IMO.

The crankshafts on these engines are cross drilled, and if you look at main journals number 2 and 5 you'll see that they end up X-drilled (cross drilled twice). So for example when the oil passage that feeds rod bearing number three comes around and lines up with the oil passage in the block all the oil that is pushed into the crank is feeding 4 passages (3 on the main bearing surface and 1 on the rod journal), not one rod journal as it should be. This is why the Dodge Viper/SRT trucks normally fry number 3 rod. I don't know why Dodge sees fit to cross drill these cranks. You can buy a Sonny Bryant, Moldex, Lunati, Callies, etc. crank and it will not be cross drilled. Cross drilling has been a discredited practice for a long time now because the rod bearings suffer from it.

Also, if you measure the cross section of the pickup passages in the pan and front cover on a Gen 2 engine you see that they are only about .4 square inches in area. They need to be double that, and are on a Gen 3. If you pull the oil pump gears out and look at the passages feeding the gears you'll see that they are tiny. The pump and pickup do not supply as much oil as we would like to see.

So where I'm going with this is we have a situation where we don't have enough oil supply to start with in a best case situation, then we throw the X drilled crank into the mix and we end up with a situation where there is insufficient oil film on the rod bearing/crank. In a situation like that I want the effects of zinc maximized as a last line of defense against metal on metal friction. So for me, considering what I've been taught, I focus on the friction reducing additives (zinc and sulphur) in an oil and reduce anything that will interfere with it, like excessive amounts of detergents.

Oil is a *very* controversial subject, and one that some people even get agitated over. I respect your opinion and always read what you have to say. I am not a smart guy by any means, but I happen to know some smart people that help me out.

If I was taught wrong about the detergent package interfering with the zinc package adhering to the bearing surfaces I would be very interested in listening to you. I would be happy to talk to you over the phone, and I'll PM you my number, but for the sake of everyone here benefiting from this maybe we can keep it on the forum.

Respectfully,

Greg

 

[Tom F&L GoR]

Hi Greg - thanks; I have thick skin and promise not to get agitated. I hope to learn and share info.

A formulator's view of the crank bearing issue is that it will be more viscosity and base oil dependent than additive. Bearings are supposed to be pressure fed and hydrodynamic conditions (i.e. one part surfing on an oil film over another part.) The bearing materials are (relative to the crank journal) very soft and usually anti-wear or friction modifier will not save them from deformation due to contact. In other words, the additives will make a smeared bearing surface look nicer, but not prevent flattening. Another reason additives are less likely to matter for bearings is because the surface active additives prefer steel or iron and don't attach to aluminum or lead. If you think of "polar" molecules as "chemically magnetic" then it helps describe their preferred affinity for ferrous materials. The best way to prevent bearing contact is higher oil flow, cooler oil, or thicker oil. Some more expensive oils contain esters, a type of synthetic, that are better at clinging to a surface. Motul uses this a lot; wonder if JGR does.

Anti wear and anti friction additives are loosely described as molecules of three parts; the active "head", the oil-soluble "tail" and a temperature dependent connecting "body." By themselves, active phosphorus or molybdenum compounds are't soluble in oil. Therefore a "tail" which is chemically similar to the host oil is attached and the soluble tail allows the insoluble head to be carried in the oil. The connecting body is designed to decompose at a certain temperature, roughly the local temperature just prior to imminent wear, if the example were an antiwear additive. Therefore the life of an antiwear additive is that it floats around in the oil, partially decomposes when it gets hot (due to impending high friction) and the active head re-attaches to the nearest ferrous metal (providing the protective layer.) If the parts get close enough, it gets rubbed off (a sacrificial dead soldier) there are others that replace it.

Sorry for the childish examples (it's how I think.)

The body section that decomposes does so at certain temperatures. A primary zinc diakyl dithiophosphate is more robust and will wait until higher temperatures; a secondary ZDDP is less robust and will decompose at lower temperatures. By mixing different versions (and in fact, some additive suppliers call them "mixed" zinc) the formulator can change when the antiwear function "happens" and in doing so change the detergent vs zinc activity.

{The other issue we haven't brought up yet is that ZDDP is also an anti-oxidant. When the oil gets hot it starts to (or wants to) turn dark and ZDDP's other role is to prevent this. Therefore in the real world, formulators add ashless antioxidants that hopefully do more of the anti-oxidant battle and free the ZDDP to combat wear. What is might mean is an all-ZDDP oil can be rendered a poor anti-wear oil if it is simply heated. You'll know when this happens because the oil will have that sulfur smell. A good break in oil should advertise that it has ashless antioxidants so that the ZDDP is not distracted into another function.}

Just as there are different types of ZDDP, there are different types of detergents, and different types of friction modifiers. Friction modifiers are also not automatically anti-wear additives. There are some that do both (moly dithiophosphates) and they are expensive and contain phosphorus. Not to poke you in the eye, but zinc is not part of a friction reducing additive and sulfur is a common "body" of many additives. With many versions of ZDDP, many detergents, and many FMs to choose from the oil can be formulated to do many things well. It is not the case that everything is a trade-off between only one function or the other.

I would therefore expect JGR should (?) have different types of ZDDP in the break in oil than in their other oils. There's a little more sophistication to all this; I'm gagging a little over the oversimplification. It's like saying your cylinder heads flow a total 800 CFM but not saying how much through the intake and through the exhaust. The balance matters.

I've been spouting off and have some chemistry, race application, and real world examples of where things didn't go bad. That doesn't mean stuff happens. If there are data points of where ZDDP-detergent interactions have been detrimental, I'm all ears.

 

[Greg Good Cylinder Heads]

Gibbs has 6 different zinc formulations they choose from, all provided by Lubrizol. They vary from fast to slow. The BR oil has more of the fast acting zinc, that is activated with less heat and load then the slower versions.

When I referred to zinc as "reducing friction" I think you knew what I meant, but feel free to poke away.

 

[Tom F&L GoR]

Greg, I'm definitely calling you since you get that kind of information from JGR. LZ is a very reputable additive company and they've been with Gibbs in one form or another since Shell was a minor co-sponsor (Interstate was primary) back in late '90's? The recent Wall Street Journal article says JGR spends $1MM/yr on lubricant development and I'm sure they're getting good advice from LZ.

Am I'm not poking, it's defining the vocabulary and not letting things get more confusing. I think much of our discussion will get very easy once defining what "high power engine", "level of interaction" and "maximum lubricant performance" mean. And whether the oil is an aid or a band-aid for a mechanical design.

 

[Greg Good Cylinder Heads]

I'll give you Lake's phone number. He'd be happy to talk to you. He's a real friendly guy.

Yes, I need some edumacation on the terminology.

The way *I* see it, the anti-friction (did I say that right ) additives are a toothpick fix for the sad oiling systems in these cars.

 

[Madduc]

Thanks Tom and Greg for a VERY informative thread,seriously!

 

[dave6666]

Around 400 sold, out of that, only about 3 people admitted on the VCA forum to having bought one.

Plus Big Brakes Dave!

I painted mine white to um match some um other white stuff.